"aquarium gravel" in pole pig? :\

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "J. Aaron Holmes" <jaholmes-at-silicon-arcana-dot-com> 

Got a couple new [to me] pole pigs the other day.
15kVA -at- 14.4kV.  One's a Westinghouse, the other an
RTE.  Both are presently empty of oil.  I popped the
lid on the RTE today, and I see what looks like white
aquarium gravel in the bottom of the can and some on
the top of the transformer (I know that's not actually
what it is, of course).  Anybody have any idea what it
is?  Both units were certified working by the utility
I purchased them from, and I've called my contact
there to inquire but haven't heard back yet.  Looks
like it would be a real pain to pull the transformer
out and dust it off...thoughts?  Other than that, no
apparent problems.  Statically tests ok, but I'm not
throwing any voltage at it until I've added oil, of
course.

Regards,
Aaron